* Do not consider themselves opportunists jumping on the Reagan bandwagon. Many of them have been Republicans for years.

And, perhaps ironically, some of them see Jesse Jackson's run for the Democratic presidential nomination as enhancing the attractiveness of the Republican Party to blacks.

The Democratic convention was ''demeaning to black Americans,'' says LeGree Daniels, a delegate here from Pennsylvania. Jackson's failure to wrest concessions from the party will make blacks ''take a second look'' at what they are getting from the Democratic Party, she said in an interview here.

Mrs. Daniels is chairman of the National Black Republican Council, an arm of the Republican National Committee. She cites several things she likes about the Reagan record so far. Among them:

1. His signing of the bill declaring the birthday of the late Martin Luther King Jr., civil rights leader and Nobel Peace prize winner, a national holiday.

2. His signing of the extension of the civil rights bill.

The President originally opposed both bills but later changed his mind. Such hesitation does not bother Lee Walker, a middle-management official with Sears in Chicago and a ''longtime'' Republican.

''Do I prefer a bumbling president who ends up doing the right thing, or a president with all the good intentions whose programs fail?'' Mr. Walker asks. He makes clear he prefers the former.

Walker, who came here to make an appearance before the Republican platform committee, says he appreciates having access to party decisionmakers.

But, he adds, blacks should be active in both parties.

''I don't want to give the impression that the answer to black problems is in the Republican Party. The answer is in being a part of a two-party system,'' explains Walker, who is not a delegate or alternate to the convention.

Range, who is self-employed as a political, economic, and social consultant in Jackson, has a similar view. ''If blacks aren't involved on both sides of the aisle, they don't participate,'' he said in an earlier interview in his home.

But he added, ''Just because we (some blacks) are active in Republican politics, we're not giving up on the black agenda.

''There are many people who need help from the government who are not getting it. But others get it too long or don't need it.''

Range supports the ''safety net'' of federal programs for the truly needy, he says. But breaking the ''welfare syndrome'' requires a tougher approach - one that ends payments to persons refusing to make efforts to become employed, he argues.

''The poor have many strong advocates,'' Range said, but added: ''It seems to me all they advocate is more handouts.''

Range's sentiment was echoed among blacks attending the National Black Republican Council meeting here just before the GOP convention got under way.

Catherine Van Noy, an active Republican in Brookhaven, N.Y., says she would like to see greater federal support for computer training of the unskilled.

Walt Marshall, a Chicago real estate developer and longtime Republican, calls many of the traditional programs to help the poor a ''band-aid'' approach. Like President Reagan, he sees improvement of the economy as the key to uplifting the poor.

One federal program aimed at training people for jobs is the Joint Partnership Training Act, signed into law by President Reagan. Dallas Urban League executive director Roosevelt Johnson Jr., a Democrat, says that the program has not gotten off the ground here.

Repeatedly, black delegates, alternates, and other black Republicans here said they liked the general party approach to economic and social issues. Some had suggestions on possible changes in party policy, but no suggestions for a major overhaul.

As Range and Mississippi Republican delegate Chester Smith sat in a hotel restaurant here, they discussed ways of fine-tuning federal support for small businesses.

''If you participate (in the Republican Party) you get a chance to express yourselves,'' Mr. Smith said.

On the south side of Dallas, a predominantly black area, laundry owner Hudson W. Griffin, a Republican for more than 25 years, put it this way: ''Unless you're in the ball game, you can't play ball.''